On the various manufacturers' websites I see the input wattage, but what do these lamps equate to in Tungsten terms ? For example: Is a 30 watt Z50 Zylight putting out 30 watts at full wick ? Are there equivalents to 300 and 500 watt tunsten floods ?

I've seen a (roughly) 12' x 12" display, which might have been the Litepanel product. The demonstrator suggested it was the equivalent of a 650 watt tungsten lamp. I guess it comes down to measuring lumens at different points.

Perhaps when there are more similar sized products offered someone might publish a piece comparing them. There are a few small head products already.

Aside from the prices - I guess manufacturers are recovering development costs and also maybe pricing for novelty value - LCD seems to be quite user friendly. Their efficiency reduces the tendency to cook a subject at short range.